Friday evening Google announced a new change in their search algorithms. Sites with too many "valid copyright removal notices" will be penalized in search results. This decision seems to be in response to copyright holders' concerns and is most likely to penalize filesharing sites.

However, Google has clarified that such changes should not affect "popular user-generated content sites" setting the stage for YouTube, as well as a number of other sites that contain pirated music in such content, to escape penalties.

Google's announcement and subsequent statements to the press leave out a lot of details but here's the basic news:

"Starting next week, we will begin taking into account a new signal in our rankings: the number of valid copyright removal notices we receive for any given site. Sites with high numbers of removal notices may appear lower in our results. This ranking change should help users find legitimate, quality sources of content more easily."

Since that statement was released on Friday, Google revealed a bit more information to Danny Sullivan at Search Engine Land:

"Google told me today that the new penalty will look beyond just the number of notices. It will also take into account other factors, specifics that Google won’t reveal, but with the end result that YouTube — as well as other popular sites beyond YouTube — aren’t expected to be hit."

"What other sites? Examples Google gave me include Facebook, IMDB, Tumblr and Twitter. But it’s not that there’s some type of 'whitelist' of sites. Rather, Google says the algorithm automatically assesses various factors or signals to decide if a site with a high number of copyright infringement notices against it should also face a penalty."

In an earlier post Sullivan points to this list of domains from the Google Transparency Report as the likely recipients of downgrades in search results. However, Google clarified "that just because a site is on that page doesn’t mean it will be hit with a penalty."

Though Google is stating that the algorithm will do the work, they've revealed in the past that they will affect things manually as needed. So if they want certain websites to move forward without penalty, the most obvious example being YouTube, they can make that happen by hand.

There's likely to be a lot of press in coming days as well as clarifications from Google but the real information will come as Google watchers analyse future search results.

If you're interested in digging deeper into this issue and the background regarding both Google and YouTube, check out Aaron Wall's extended post at SEO Book.